Three-electrode vacuum tube



Feb. 20, 1934. J 1 U 1,947,514

THREE-ELECTRODE VACUUM TUBE Original Filed Aug. 29. 1931 INVENTORJACQUES BIGUET ATTORNEY Patented Feb. 20, 1934 THREE-ELECTRODE VACUUMTUBE Jacques Biguet,

Lyons, France Original application August 29, 1931, Serial No. 496,554,and in France October 23, 1915. Divided and this application May 28,1932.

Serial No. 614,243

5 Claims.

This invention relates to improvements in vacuum tubes of the audiontype and more particularly to a type of anode construction for use insuch tubes. The subject matter of this application is divided out of myapplication, Serial No. 496,554, filed August 29, 1921, which hasmatured into Patent No. 1,861,107, dated May 31, 1932, and wherein themeans for mounting the several elements of the tube is particularlyclaimed.

In the annexed drawing, wherein like reference characters are used todesignate similar elements, Figures 1 and 2 illustrate two views of theapparatus, taken from two opposite directions.

Figure 3 is a view of the stem with the leads sealed therein.

Figure 4 is a similar view showing the leads in their final shape beforemounting the several electrodes.

Figures 5, 6 and 7 illustrate perspective views of difierent types ofplate electrodes that may be used.

Into the bulb A is introduced and sealed into the neck of the bulb, inthe same way as in the ordinary incandescent lamp, a stem or support Bon which are previously fixed or mounted the plate C, grid D and thefilament E.

Each of these elements is connected to the pins of the base F byconductors or leads sealed into the stem B.

This stern, represented alone in Figure 3, is formed, as in ordinarylamps, of a flared glass tube with a press into which are sealed theleads a, b, c, (1, each of which consists of an outside lead c ofcopper, a platinum or equivalent leading-in wire f, and an inside lead9, preferably of nickel or chrome-nickel.

These leads are during manufacture of the tube given the definite shapeillustrated in Figure 4. The plate (Figure 5) is formed of a sheet ofmetal rolled into cylindrical shape and extended at the middle by one ortwo hooks m and m each provided with a recess, into which is introducedand pressed the corresponding lead It. Another meth 0d of constructioncan also be employed, such as illustrated in Figure 6. Instead of asolid plate it can be made of a trellis or tissue of tungsten wire asshown in Figure '7.

The coil or grid D illustrated is composed of a wire of suitablediameter, preferably of tungsten or any other highly refractory metal,rolled helically and having two straight ends which may be clamped orsoldered to the ends of a cross bar it which is carried by the lead d,as indicated in Figure 4.

The rectilinear filament is stretched between the two leads 2' and :i,shown in the same figure, which may be flattened or lengthened in anymanner to give them sufficient elasticity with a View to removing anydanger of the filaments breaking.

The three elements of the device being concentrically placed give theirmaximum effectiveness, especially with regard to the phenomenon ofsaturation. Moreover, the squat shape of the whole ensures a greatersolidity to the apparatus.

When it is employed as generator of maintained waves, the energyexpended can be such that the cylindrical plate may be carried to a hightemperature; in that case it is advisable to employ a plate ofrefractory metal such as tungsten. Likewise, the conductors or leadsserving as supports to the three elements may be of molybdenum or oftungsten; their section may be rectangular instead of being circular, ordivided into several wires of minimum section in order to ensure theircooling.

I claim:

1. An electron discharge tube having a cathode and a control electrodemade of a trellis of wire.

and a plate electrode 2. An electron discharge tube having a cathode anda control electrode and a plate electrode made of a trellis of tungstenwire.

3. In an electron discharge tube, an anode made of metallic wire cloth.

grid.

JACQUES BIGUET.

CERTIFICATE OF (IORREGTION.

Patent No. 1,947,514. February 20, 1934.

J AGOUES BIGUET.

tit'ied that the above numbered patent was erroneously issued whereassaid Letters Patent should have been issued to Radio Corporation ofAmerica, New York, N. Y., a corporation of Delaware, as assignee of theentire interest in said invention as shown by the records of assignmentsin this office; and that the said Letters Patent should be read withthis correction therein that the same may conform to the record of thecase in the Patent Office.

Signed and sealed this 19th day of June, A. D. 1934.

Bryan M. Battey It is hereby eer to the inventor said "Jacques Biguet"Acting Commissioner of Patents,

(Seal)

